16728161 has 4 divisors (see below), whose sum is σ = 17117232. Its totient is φ = 16339092.

The previous prime is 16728149. The next prime is 16728163. The reversal of 16728161 is 16182761.

It is a happy number.

16728161 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16182761 = 7 ⋅2311823.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16728161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16728163) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 194471 + ... + 194556.

It is an arithmetic number, because the mean of its divisors is an integer number (4279308).

Almost surely, 2^16728161 is an apocalyptic number.

It is an amenable number.

16728161 is a deficient number, since it is larger than the sum of its proper divisors (389071).

16728161 is an equidigital number, since it uses as much as digits as its factorization.

16728161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 389070.

The product of its digits is 4032, while the sum is 32.

The square root of 16728161 is about 4090.0074572059. The cubic root of 16728161 is about 255.7502497938.

The spelling of 16728161 in words is "sixteen million, seven hundred twenty-eight thousand, one hundred sixty-one".